<!DOCTYPE html>
<html>
    <head>
        <style>
            span {
                color: red;
            }
        </style>

        <script>
            function boom(){
                var span1 = document.getElementById("span1");
                span1.innerHTML = "炸弹已爆炸";
            }
          setTimeout(boom,10000);

            /*var num = 1;
            function print(){
                num += 1;
                console.log("你好" + num);
            }
            var inter =window.setInterval(print,5000);
            function stop(){
                clearInterval(inter);
            }*/
        </script>
    </head>
    <body>
  
        <!--<input type="button" value="关闭" onclick="stop()">  -->
        <span id="span1">倒计时10秒爆炸</span>



    </body>
</html>